[Mononeuritis multiplex in a case of primary macroglobulinemia (author's transl)].

A case of Waldenström's disease with peripheral nerve involvement resembling mononeuritis multiplex is described. The various etiopathogenic mechanisms generally cited in connection with peripheral neuropathies observed in cases of macroglobulinemia, most often of the polyneuritic type, are discussed in turn : nerve infiltration by lymphocytes, intervention of an immunologic mechanism through the agency of paraprotein links with amyloidosis. However, the reported case differs from habitual cases on account of the asymmetry of the nerve involvement and the discovery of vasculitic lesions on muscle biopsy. The hypothesis of ischemic neuropathy associated with serum hyperviscosity is proposed and confirmed by the clinical improvement and reduction of macroglobulin obtained by repeated plasma exchanges and administration of Chlorambucil.